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Subject[PATCH V2 3/5] gpio: add support for AMS AS3722 gpio driver
Date
The AS3722 is a compact system PMU suitable for mobile phones, tablets etc.

Add a driver to support accessing the 8 GPIOs found on the AMS AS3722
PMIC using gpiolib.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Florian Lobmaier <florian.lobmaier@ams.com>
---
Changes from V1:
- Nit cleanups in driver and use module_platform_driver.

.../devicetree/bindings/gpio/gpio-as3722.txt | 62 +++
drivers/gpio/Kconfig | 6 +
drivers/gpio/Makefile | 1 +
drivers/gpio/gpio-as3722.c | 435 ++++++++++++++++++++
4 files changed, 504 insertions(+), 0 deletions(-)
create mode 100644 Documentation/devicetree/bindings/gpio/gpio-as3722.txt
create mode 100644 drivers/gpio/gpio-as3722.c

diff --git a/Documentation/devicetree/bindings/gpio/gpio-as3722.txt b/Documentation/devicetree/bindings/gpio/gpio-as3722.txt
new file mode 100644
index 0000000..8d46dd3
--- /dev/null
+++ b/Documentation/devicetree/bindings/gpio/gpio-as3722.txt
@@ -0,0 +1,62 @@
+GPIO of AMS AS3722 PMIC.
+
+Name of GPIO subnode should be "gpio".
+Required properties:
+--------------------
+- #address-cells: Number of address of the sub node of this node. Must be 1.
+- #size-cells: Size of addess cells. Must be 1.
+
+Sub node:
+--------
+The sub nodes provides the configuration of each GPIO pins. The properties of the
+nodes are as follows:
+
+Required subnode properties:
+---------------------------
+reg: The GPIO number on which the properties need to be applied.
+
+Optional subnode properties:
+---------------------------
+bias-pull-up: The Pull-up for the pin to be enable.
+bias-pull-down: Pull down of the pins to be enable.
+bias-high-impedance: High impedance of the pin to be enable.
+open-drain: Pin is open drain type.
+function: IO functionality of the pins. The valid options are:
+ gpio, intrrupt-output, vsup-vbat-low-undeb, interrupt-input,
+ pwm-input, voltage-stby, oc-powergood-sd0, powergood-output,
+ clk32k-output, watchdog-input, soft-reset-input, pwm-output,
+ vsup-vbat-low-deb, oc-powergood-sd6
+ Missing the function property will set the pin in GPIO mode.
+
+ams,enable-gpio-invert: Enable invert of the signal on GPIO pin.
+
+Example:
+ ams3722:: ams3722 {
+ compatible = "ams,as3722";
+ ...
+ gpio-controller;
+ #gpio-cells = <2>;
+
+ gpio {
+ #address-cells = <1>;
+ #size-cells = <0>;
+ gpio@0 {
+ reg = <0>;
+ bias-pull-down;
+ };
+
+ gpio@1 {
+ reg = <1>;
+ bias-pull-up;
+ ams,enable-gpio-invert;
+ };
+
+ ...
+ gpio@5 {
+ reg = <5>;
+ unction = "clk32k-output";
+ };
+ ...
+ };
+ ...
+ };
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index b6ed304..544a612 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -368,6 +368,12 @@ config GPIO_ARIZONA
help
Support for GPIOs on Wolfson Arizona class devices.

+config GPIO_AS3722
+ bool "AMS AS3722 PMICs GPIO"
+ depends on MFD_AS3722
+ help
+ Select this option to enable GPIO driver for the AMS AS3722 PMIC.
+
config GPIO_MAX7300
tristate "Maxim MAX7300 GPIO expander"
depends on I2C
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index 98e23eb..d1715a0 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -16,6 +16,7 @@ obj-$(CONFIG_GPIO_ADP5520) += gpio-adp5520.o
obj-$(CONFIG_GPIO_ADP5588) += gpio-adp5588.o
obj-$(CONFIG_GPIO_AMD8111) += gpio-amd8111.o
obj-$(CONFIG_GPIO_ARIZONA) += gpio-arizona.o
+obj-$(CONFIG_GPIO_AS3722) += gpio-as3722.o
obj-$(CONFIG_GPIO_BT8XX) += gpio-bt8xx.o
obj-$(CONFIG_GPIO_CLPS711X) += gpio-clps711x.o
obj-$(CONFIG_GPIO_CS5535) += gpio-cs5535.o
diff --git a/drivers/gpio/gpio-as3722.c b/drivers/gpio/gpio-as3722.c
new file mode 100644
index 0000000..44b5a75
--- /dev/null
+++ b/drivers/gpio/gpio-as3722.c
@@ -0,0 +1,435 @@
+/*
+ * gpiolib support for ams AS3722 PMICs
+ *
+ * Copyright (C) 2013 ams AG
+ *
+ * Author: Florian Lobmaier <florian.lobmaier@ams.com>
+ * Author: Laxman Dewangan <ldewangan@nvidia.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ */
+
+#include <linux/gpio.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mfd/as3722.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+#define AS3722_MAX_GPIO 8
+#define AS3722_GPIO_MODE_PROP_PULL_UP 0x1
+#define AS3722_GPIO_MODE_PROP_PULL_DOWN 0x2
+#define AS3722_GPIO_MODE_PROP_HIGH_IMPED 0x4
+#define AS3722_GPIO_MODE_PROP_OPEN_DRAIN 0x8
+
+struct as3722_gpio_control {
+ bool enable_gpio_invert;
+ unsigned mode_prop;
+ int io_function;
+};
+
+struct as3722_gpio {
+ struct gpio_chip gpio_chip;
+ struct device *dev;
+ struct as3722 *as3722;
+ struct as3722_gpio_control gpio_control[AS3722_MAX_GPIO];
+};
+
+struct as3722_gpio_mode_property {
+ const char *prop;
+ u32 prop_val;
+};
+
+static char const *as3722_gpio_iosf[] = {
+ "gpio",
+ "intrrupt-output",
+ "vsup-vbat-low-undeb",
+ "interrupt-input",
+ "pwm-input",
+ "voltage-stby",
+ "oc-powergood-sd0",
+ "powergood-output",
+ "clk32k-output",
+ "watchdog-input",
+ "unused",
+ "soft-reset-input",
+ "pwm-output",
+ "vsup-vbat-low-deb",
+ "oc-powergood-sd6",
+ "unused1"
+};
+
+static const struct as3722_gpio_mode_property const as3722_gpio_mode_props[] = {
+ {
+ .prop = "bias-pull-up",
+ .prop_val = AS3722_GPIO_MODE_PROP_PULL_UP,
+ }, {
+ .prop = "bias-pull-down",
+ .prop_val = AS3722_GPIO_MODE_PROP_PULL_DOWN,
+ }, {
+ .prop = "bias-high-impedance",
+ .prop_val = AS3722_GPIO_MODE_PROP_HIGH_IMPED,
+ }, {
+ .prop = "open-drain",
+ .prop_val = AS3722_GPIO_MODE_PROP_OPEN_DRAIN,
+ },
+};
+
+static int as3722_gpio_get_mode(unsigned gpio_mode_prop, bool input)
+{
+ if (gpio_mode_prop & AS3722_GPIO_MODE_PROP_HIGH_IMPED)
+ return -EINVAL;
+
+ if (gpio_mode_prop & AS3722_GPIO_MODE_PROP_OPEN_DRAIN) {
+ if (gpio_mode_prop & AS3722_GPIO_MODE_PROP_PULL_UP)
+ return AS3722_GPIO_MODE_IO_OPEN_DRAIN_PULL_UP;
+ return AS3722_GPIO_MODE_IO_OPEN_DRAIN;
+ }
+ if (input) {
+ if (gpio_mode_prop & AS3722_GPIO_MODE_PROP_PULL_UP)
+ return AS3722_GPIO_MODE_INPUT_PULL_UP;
+ else if (gpio_mode_prop & AS3722_GPIO_MODE_PROP_PULL_DOWN)
+ return AS3722_GPIO_MODE_INPUT_PULL_DOWN;
+ return AS3722_GPIO_MODE_INPUT;
+ }
+ if (gpio_mode_prop & AS3722_GPIO_MODE_PROP_PULL_DOWN)
+ return AS3722_GPIO_MODE_OUTPUT_VDDL;
+ return AS3722_GPIO_MODE_OUTPUT_VDDH;
+}
+
+static inline struct as3722_gpio *to_as3722_gpio(struct gpio_chip *chip)
+{
+ return container_of(chip, struct as3722_gpio, gpio_chip);
+}
+
+static int as3722_gpio_get(struct gpio_chip *chip, unsigned offset)
+{
+ struct as3722_gpio *as3722_gpio = to_as3722_gpio(chip);
+ struct as3722 *as3722 = as3722_gpio->as3722;
+ int ret;
+ u32 reg;
+ u32 control;
+ u32 val;
+ int mode;
+ int invert_enable;
+
+ ret = as3722_read(as3722, AS3722_GPIOn_CONTROL_REG(offset), &control);
+ if (ret < 0) {
+ dev_err(as3722_gpio->dev,
+ "GPIO_CONTROL%d_REG read failed: %d\n", offset, ret);
+ return ret;
+ }
+
+ invert_enable = !!(control & AS3722_GPIO_INV);
+ mode = control & AS3722_GPIO_MODE_MASK;
+ switch (mode) {
+ case AS3722_GPIO_MODE_INPUT:
+ case AS3722_GPIO_MODE_INPUT_PULL_UP:
+ case AS3722_GPIO_MODE_INPUT_PULL_DOWN:
+ case AS3722_GPIO_MODE_IO_OPEN_DRAIN:
+ case AS3722_GPIO_MODE_IO_OPEN_DRAIN_PULL_UP:
+ reg = AS3722_GPIO_SIGNAL_IN_REG;
+ break;
+ case AS3722_GPIO_MODE_OUTPUT_VDDH:
+ case AS3722_GPIO_MODE_OUTPUT_VDDL:
+ reg = AS3722_GPIO_SIGNAL_OUT_REG;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ ret = as3722_read(as3722, reg, &val);
+ if (ret < 0) {
+ dev_err(as3722_gpio->dev,
+ "GPIO_SIGNAL_IN_REG read failed: %d\n", ret);
+ return ret;
+ }
+
+ val = !!(val & AS3722_GPIOn_SIGNAL(offset));
+ return (invert_enable) ? !val : val;
+}
+
+static void as3722_gpio_set(struct gpio_chip *chip, unsigned offset,
+ int value)
+{
+ struct as3722_gpio *as3722_gpio = to_as3722_gpio(chip);
+ struct as3722 *as3722 = as3722_gpio->as3722;
+ int en_invert = as3722_gpio->gpio_control[offset].enable_gpio_invert;
+ u32 val;
+ int ret;
+
+ if (value)
+ val = (en_invert) ? 0 : AS3722_GPIOn_SIGNAL(offset);
+ else
+ val = (en_invert) ? AS3722_GPIOn_SIGNAL(offset) : 0;
+
+ ret = as3722_update_bits(as3722, AS3722_GPIO_SIGNAL_OUT_REG,
+ AS3722_GPIOn_SIGNAL(offset), val);
+ if (ret < 0)
+ dev_err(as3722_gpio->dev,
+ "GPIO_SIGNAL_OUT_REG update failed: %d\n", ret);
+}
+
+static int as3722_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
+{
+ struct as3722_gpio *as3722_gpio = to_as3722_gpio(chip);
+ struct as3722 *as3722 = as3722_gpio->as3722;
+ int mode;
+
+ mode = as3722_gpio_get_mode(as3722_gpio->gpio_control[offset].mode_prop,
+ true);
+ if (mode < 0) {
+ dev_err(as3722_gpio->dev,
+ "Input direction for GPIO %d not supported\n", offset);
+ return mode;
+ }
+
+ if (as3722_gpio->gpio_control[offset].enable_gpio_invert)
+ mode |= AS3722_GPIO_INV;
+
+ return as3722_write(as3722, AS3722_GPIOn_CONTROL_REG(offset), mode);
+}
+
+static int as3722_gpio_direction_output(struct gpio_chip *chip,
+ unsigned offset, int value)
+{
+ struct as3722_gpio *as3722_gpio = to_as3722_gpio(chip);
+ struct as3722 *as3722 = as3722_gpio->as3722;
+ int mode;
+
+ mode = as3722_gpio_get_mode(as3722_gpio->gpio_control[offset].mode_prop,
+ false);
+ if (mode < 0) {
+ dev_err(as3722_gpio->dev,
+ "Output direction for GPIO %d not supported\n", offset);
+ return mode;
+ }
+
+ as3722_gpio_set(chip, offset, value);
+ if (as3722_gpio->gpio_control[offset].enable_gpio_invert)
+ mode |= AS3722_GPIO_INV;
+ return as3722_write(as3722, AS3722_GPIOn_CONTROL_REG(offset), mode);
+}
+
+static int as3722_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
+{
+ struct as3722_gpio *as3722_gpio = to_as3722_gpio(chip);
+
+ return as3722_irq_get_virq(as3722_gpio->as3722, offset);
+}
+
+static int as3722_gpio_request(struct gpio_chip *chip, unsigned offset)
+{
+ struct as3722_gpio *as3722_gpio = to_as3722_gpio(chip);
+
+ if (as3722_gpio->gpio_control[offset].io_function)
+ return -EBUSY;
+ return 0;
+}
+
+static int as3722_gpio_set_config(struct as3722_gpio *as3722_gpio,
+ unsigned int gpio)
+{
+ struct as3722 *as3722 = as3722_gpio->as3722;
+ int ret = 0;
+ u8 val = 0;
+
+ val = AS3722_GPIO_IOSF_VAL(as3722_gpio->gpio_control[gpio].io_function);
+ ret = as3722_update_bits(as3722, AS3722_GPIOn_CONTROL_REG(gpio),
+ AS3722_GPIO_IOSF_MASK, val);
+ if (ret < 0)
+ dev_err(as3722->dev,
+ "GPIO%d_CTRL_REG update failed %d\n", gpio, ret);
+ return ret;
+}
+
+static int as3722_gpio_init_configs(struct as3722_gpio *as3722_gpio)
+{
+ int ret;
+ unsigned int i;
+
+ for (i = 0; i < AS3722_MAX_GPIO; i++) {
+ if (!as3722_gpio->gpio_control[i].io_function)
+ continue;
+
+ ret = as3722_gpio_set_config(as3722_gpio, i);
+ if (ret < 0) {
+ dev_err(as3722_gpio->dev,
+ "GPIO %d config failed %d\n", i, ret);
+ return ret;
+ }
+ }
+ return 0;
+}
+
+static int as3722_gpio_dt_subnode(struct as3722_gpio *as3722_gpio,
+ struct device_node *child, int gpio)
+{
+ const char *iosf;
+ int i;
+ int ret;
+ bool found;
+ unsigned prop_val = 0;
+
+ for (i = 0; i < ARRAY_SIZE(as3722_gpio_mode_props); ++i) {
+ found = of_property_read_bool(child,
+ as3722_gpio_mode_props[i].prop);
+ if (found)
+ prop_val |= as3722_gpio_mode_props[i].prop_val;
+ }
+ as3722_gpio->gpio_control[gpio].mode_prop = prop_val;
+
+ ret = of_property_read_string(child, "function", &iosf);
+ if (!ret) {
+ found = false;
+ for (i = 0; i < ARRAY_SIZE(as3722_gpio_iosf); ++i) {
+ if (!strcmp(as3722_gpio_iosf[i], iosf)) {
+ found = true;
+ break;
+ }
+ }
+ if (found)
+ as3722_gpio->gpio_control[gpio].io_function = i;
+ else
+ dev_warn(as3722_gpio->dev,
+ "Child %s io function is invalid\n",
+ child->name);
+ }
+
+ as3722_gpio->gpio_control[gpio].enable_gpio_invert =
+ of_property_read_bool(child, "ams,enable-gpio-invert");
+ return 0;
+}
+
+static int as3722_get_gpio_dt_data(struct platform_device *pdev,
+ struct as3722_gpio *as3722_gpio)
+{
+ struct device_node *np;
+ struct device_node *child;
+ unsigned int gpio;
+ int ret;
+
+ np = of_get_child_by_name(pdev->dev.parent->of_node, "gpio");
+ if (!np) {
+ dev_err(&pdev->dev, "Device is not having gpio node\n");
+ return -ENODEV;
+ }
+
+ for_each_child_of_node(np, child) {
+ ret = of_property_read_u32(child, "reg", &gpio);
+ if (ret < 0) {
+ dev_warn(&pdev->dev,
+ "reg property not present in node %s\n",
+ child->name);
+ continue;
+ }
+ if (gpio >= AS3722_MAX_GPIO) {
+ dev_warn(&pdev->dev,
+ "GPIO number %d is more than supported\n", gpio);
+ continue;
+ }
+ ret = as3722_gpio_dt_subnode(as3722_gpio, child, gpio);
+ if (ret < 0)
+ dev_warn(&pdev->dev, "gpio %s node parse failed: %d\n",
+ child->name, ret);
+ }
+ return 0;
+}
+
+static const struct gpio_chip as3722_gpio_chip = {
+ .label = "as3722-gpio",
+ .owner = THIS_MODULE,
+ .direction_input = as3722_gpio_direction_input,
+ .get = as3722_gpio_get,
+ .direction_output = as3722_gpio_direction_output,
+ .set = as3722_gpio_set,
+ .to_irq = as3722_gpio_to_irq,
+ .request = as3722_gpio_request,
+ .can_sleep = 1,
+ .ngpio = AS3722_MAX_GPIO,
+ .base = -1,
+};
+
+static int as3722_gpio_probe(struct platform_device *pdev)
+{
+ struct as3722 *as3722 = dev_get_drvdata(pdev->dev.parent);
+ struct as3722_gpio *as3722_gpio;
+ int ret;
+
+ as3722_gpio = devm_kzalloc(&pdev->dev, sizeof(*as3722_gpio),
+ GFP_KERNEL);
+ if (!as3722_gpio)
+ return -ENOMEM;
+
+ ret = as3722_get_gpio_dt_data(pdev, as3722_gpio);
+ if (ret < 0)
+ return ret;
+
+ as3722_gpio->as3722 = as3722;
+ as3722_gpio->dev = &pdev->dev;
+ as3722_gpio->gpio_chip = as3722_gpio_chip;
+ as3722_gpio->gpio_chip.dev = &pdev->dev;
+ as3722_gpio->gpio_chip.of_node = pdev->dev.parent->of_node;
+
+ platform_set_drvdata(pdev, as3722_gpio);
+
+ ret = as3722_gpio_init_configs(as3722_gpio);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "gpio_init_regs failed\n");
+ return ret;
+ }
+
+ ret = gpiochip_add(&as3722_gpio->gpio_chip);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "Could not register gpiochip, %d\n",
+ ret);
+ return ret;
+ }
+ return 0;
+}
+
+static int as3722_gpio_remove(struct platform_device *pdev)
+{
+ struct as3722_gpio *as3722_gpio = platform_get_drvdata(pdev);
+
+ return gpiochip_remove(&as3722_gpio->gpio_chip);
+}
+
+static const struct of_device_id of_as3722_gpio_match[] = {
+ { .compatible = "ams,as3722-gpio", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, of_as3722_gpio_match);
+
+static struct platform_driver as3722_gpio_driver = {
+ .driver = {
+ .name = "as3722-gpio",
+ .owner = THIS_MODULE,
+ .of_match_table = of_as3722_gpio_match,
+ },
+ .probe = as3722_gpio_probe,
+ .remove = as3722_gpio_remove,
+};
+
+module_platform_driver(as3722_gpio_driver);
+
+MODULE_ALIAS("platform:as3722-gpio");
+MODULE_DESCRIPTION("GPIO interface for AS3722 PMICs");
+MODULE_AUTHOR("Florian Lobmaier <florian.lobmaier@ams.com>");
+MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
+MODULE_LICENSE("GPL");
--
1.7.1.1


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